Organo-phosphorus compounds containing perfluoroalkyl radicals and their application to cellulosic textiles

ABSTRACT

Perfluoroalkyl iodide monomer and telomer ester adducts of diethyl vinylphosphonate were prepared by free radical addition. Iodine of these adducts was replaced by hydrogen, and derivatives of the reduced phosphonate adducts were prepared, which include phosphonic acids, acid chlorides, and aziridinyl phosphine oxides. The aziridinyl phosphine oxides are used to impart oil and water repellency to cellulosic textiles. The other derivatives are useful as chemical intermediates as well as potential forming agents.

United States Patent Chance et al.

[ 51 March 6, 1973 ORGANO-PIIOSPI'IORUS COMPOUNDS CONTAININGPERFLUOROALKYL RADICALS AND THEIR APPLICATION TO CELLULOSIC TEXTILESInventors: Leon H. Chance; Jerry P. Moreau, both of New Orleans, La.

Assignee: The United States of America as represented by the Secretaryof Agriculture Filed: June9, 1971 Appl. No.: 151,556 I Related us.Application Data Division of Ser. No. 843,200, July 18, 1969, Pat. No.3,639,144.

US. Cl. ..8/116 P, 8/115.6, 8/116.2, 8/120,117/135.5,117/143 R, 260/239EP, 260/502.4 R, 260/502.4 P, 260/653,

260/983, 260/986, 252/350 Int. Cl. ..C07f 9/56, C07f 9/40, D06m 13/28Field of Search ..8/1l6 P, 116.2, 120;

References Cited UNITED STATES PATENTS Bittles et al ..260/955 9/1965Chance ..8/l16 P 3,300,274 6/1967 Pittman et a1. ..8/1 16.2 3,312,5204/1967 Kenoga ..8/116.2 3,406,004 10/1968 Tesoro et a1 ....8/1203,446,570 5/1969 Sweeney et ....8/120 3,563,999 2/1971 Anello et al.........8/116.2 3,575,961 4/1971 Tesoro et al ..8/1 16.2

OTHER PUBLICATIONS Bennett et al., J. Chem. Soc., 3598-3603 (1954).Emeleus et al., J. Chem. Soc., 375-381 (1959). Brace, J. Org. Chem. 26,3197-3201 (1961).

Primary Examiner-George F. Lesmes Assistant Examiner-J. CannonAttorney-R. Hoffman et al.

[5 7] ABSTRACT 3 Claims, No Drawings ORGANO-PI-IOSPHORUS COMPOUNDSCONTAINING PERFLUOROALKYL RADICALS AND THEIR APPLICATION TO CELLULOSICTEXTILES This application is a division of application Ser. No. 843,200,filed July 18, 1969, and now US. Pat. No. 3,639,144.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to perfluoroalkyl adducts of diethylvinylphosphonate, to derivatives thereof, to the preparation thereof,and to processes for imparting improved properties to cellulosictextiles by treating said textiles with certain of the perfluoroalkylphosphorus derivatives of this invention. More specifically, thisinvention relates to the preparation of perfluoroalkyl phosphonateesters and to the corresponding acids, acid chlorides, and aziridinylderivatives, useful in oil and water repellent finishes for textiles andalso useful as chemical intermediates and potential foaming agents.

DEFINITIONS:

1. .Telomers are polymers of low molecular weight such as areencountered, for example,'in the free-radical addition of an addendum XYto ethylene, which may be represented as xv +,,CH :CH x (CH -CH Y wheren is small; the process is known as telomerization. Kingzetts ChemicalEncyclopedia, 9th Ed.

2. Telomerization does not differ essentially from other polymerizationcatalyzed by free radicals. It arises merely because enough of asufficiently reactive compound is present to act as a chain transferreagent, but the concentration and reactivity are not high enough togive rise chiefly to 1,2, addition.

Carl R. Nollers Chemistry of Organic Compounds Themain object of theinstant invention is to provide new phosphonic compounds containing aperfluoroalkyl radical connected to the phosphorus atom by an ethylene(-CH CH linkage.

f A second object of the instant invention is to provide methods ofpreparing new perfluoroalkyl phosphonic compounds.

' A third object of the instant invention is to provide a process forimparting to cotton and other cellulosic materials both oil and waterrepellency using some of the new compounds of the instant invention.

A fourth object of the invention is to provide a process for impartingto cotton and other cellulosic textiles resistance to soiling andstaining.

Searching the prior art we find that a dialkyl phosphonate reacts withtetrafluoroethylene in a pressure vessel using a free radical initiatorto produce products of the general formula H(CF CH ),,PO(OR) [Neal D.Brace, J. Org. Chem. 26, 3197 (1961).] These products have a terminalhydrogen atom on the perfluoro group, and consequently are not aseffective in producing oil and water repellency as similar products inwhich the terminal hydrogen is replaced by a fluorine atom.

One improvement which is a facet of the present invention over the priorart is this. We have found-that compounds of the present inventionimpart excellent oil repellency and moderate water repellency to cellu-vlosic materials because the perfluoro group has a terminal CF groupinstead of a terminal HCF group.

In the course of investigation we have found that compounds of thegeneral formula Reducing u Fz=+1 CHa-CH agent L (0);(ORJ2-iv CHz-CH l P015 i '1 Aziridlne H J.

acid hydrolysis FOIL-(EH i. 401) L (0)1 (N-CHzCHzhJy n lu-H where n isan integer from 1 to 10, and y is an integer from 1 to 3.

In accordance with the present invention the reaction of the dialkylvinylphosphonate with the perfluoroalkyl iodide is carried out byheating in the presence of a select catalyst. Typical catalysts suitablefor the reaction are organic peroxides, such as ditertbutyl peroxide orazobisnitriles such as azobis(isobutyronitrile). Two main products areobtained from this type reaction and include the monomericperfluoroalkyl iodide adduct and a telomer in which the dialkylphosphonate moiety is dimeric. A mixture of unidentified highermolecular weight telomers are also obtained. Typical examples arerepresented by the reaction of diethyl vinylphosphonate andperfluoroheptyl iodide to give a monomeric phosphonate ester of theformula and a telomer ester of the formula Also in accordance with thepresent invention the iodine atom is removed from the 'perfluoroalkylphosphonate esters by a reducing agent, and replaced by a hydrogen atom.The preferred reducing agent is zinc metal and hydrochloric acid.Typical reduced phosphonate esters are represented by a monomer of theformula and a telomer of the formula The conversion of the reducedphosphonate esters to the phosphonic acids is carried out by hydrolysisin the presence of a mineral acid. The preferred acid is hydrochloricacid. The conversion of the phosphonic acids to the phosphonicdichloride is carried out by heating with PC1 in a suitable solvent. Thepreferred solvent is carbon tetrachloride.

The conversion of the phosphonic dichloride to the diaziridinylderivative is carried out by reaction with aziridine in a suitableorganic solvent in the presence of an acid acceptor. A variety ofsolvents are suitable and include benzene and chlorinated solvents suchas carbon tetrachloride or methylene chloride. Suitable acid acceptorsinclude tertiary organic bases such as triethylamine and inorganic basessuch as sodium or potassium hydroxide. The preferred base istriethylamine. Typical diaziridinyl derivatives are represented by amonomer of the formula and a telomer of the formula Each of the new typeperfluoroalkyl phosphonic compounds mentioned above is useful as aprecursor to the type compound which follows. Finally, the aziridinylderivatives are useful as oil and water repellents for textiles,particularly for cotton or other cellulosic textiles, and for paper. Thephosphonic acid derivatives have use as potential foaming agents.

The perfluroroalkyl aziridinyl phosphine oxide can be applied tocellulosic materials from a variety of so]- vents. Suitable solvents arewater, alcohols such as ethanol or methanol and glycol ethers such asethylene glycol monoethyl ether. The preferred solvent is water. Thepreferred concentration of the phosphine oxides used in the solutionsdepends on the particular phosphine oxide being used and on the degreeof oil and water repellency desired, and may vary about from 3 topercent by weight of the total solution. Aqueous solutions arepreferred.

Polymerization of the phosphine oxides on the cellulosic material iscarried out in the presence of latent acid catalysts such as magnesiumchloride, zinc nitrate, or zinc fluoborate. The catalyst concentrationmay vary about from 0.5 to 2 percent by weight of the total solution,the preferred concentration depending on the concentration of thephosphine oxide.

The polymerization on cellulosic materials may be carried out byimpregnating the cellulosic material with a solution of the phosphineoxide and catalyst, drying, and curing at temperatures ranging aboutfrom 120 to 160C. for periods of time about from 3 minutes to 30minutes, the longer times being used with the lower temperatures.

Cotton fabrics which have been treated by the processes of thisinvention are tested for oil repellency, water repellency, and drycleaning durability by AATCC Standard Method No. 118-1966T, 22-1964, and86-1963T, respectively. These tests are recommended by the AmericanAssociation of Textile Chemists and Colorists. Laundering durabilitytests on the cotton fabrics are performed in an automatic hometypewashing machine using a detergent, followed by a 50 minute drying cyclein a tumble dryer. Screening laundry tests were carried out in aTergitometer using a detergent.

The following examples illustrate procedures that have been successfullyused in carrying out the invention and are not meant as a limitationthereof.

PREPARATION OF PERFLUOROALKYLPHOSPHONIC COMPOUNDS EXAMPLE 1 Diethyl 1-iodol H, 2H, 21-1-perfluorononylphosphonate (Ia) and tetraethyl 1-(l1-l,11-l-perfluorooctyl )-3-iodo-1 ,3-trimethylenediphosphonate (1b)Diethylvinylphosphonate (57.8g., 0.35 mole) and perfluoroheptyl iodide(192.1 g, 0.39 mole) were placed into a three-neck rib flask equippedwith a magnetic stirrer, thermometer, gas inlet tube, and condenserconnected to a mercury air trap. Light was excluded by covering theflask with aluminum foil. Azobis(isobutyronitrile) catalyst (1.15 g,0.007 mole) was added and the system flushed with nitrogen. The flaskwas heated in a water bath to at which temperature an exothermicreaction began. An ice bath was used to keep the temperature below 150C.Reaction temperature was then maintained at approximately C for 6 hours.Unreacted material g) was removed by vacuum distillation below 50 (0.3mm). The residue (153.1 g) was crude mixed iodo-esters (I). A smallamount of I was distilled under vacuu. The iodo-adduct (Ia) had bpl08114C (0.03 mm); n D 1.3930. Anal. Calcd. for C T-1 1 10 P: C, 23.65;H, 1.99; F, 43.17; 1, 19.22; P, 4.69; mol. wt., 660. Found: C, 23.81; H,2.02; F, 43.17; 1, 19.09; P, 4.90; mol. wt. (benzene), 650.

The iodo-telomer (1b) had bp 1446 (0.03 mm); n D 1.4074. Anal. Calcd.for C,,,H F,,,IO,,P C, 27.69; H, 3.18; F, 34.57; 1, 15.40; P, 7.52; mol.wt., 824. Found: C, 27.80; H, 3.14; F, 34.55; 1, 15.18; P, 7.24; mol.wt. (benzene), 830.

EXAMPLE 2 Diethyl 1H, 1H, 2H, 2H-perfluorononylphosphonate (Ila) andtetraethyl l-(lH, 1H-perf1uoroocty1)-1,3-

trimethylenediphosphonate (11b) A slurry of 30 g of zinc dust in 200 mlof ethanol was heated in a water bath to 60C with stirring. An ethanolicsolution of 1 (153.1 g) and 75 m1 of cone. hydrochloric acid were addedfrom separate dropping funnels within 30 minutes. The bath temperaturewas raised to 70 then 15 g of zinc and 40 ml of hydrochloric acid wereadded in increments over 1 hour. The mixture was heated an additionalhour at 80C, cooled, filtered and concentrated on a rotary evaporator.The concentrate was washed with distilled water, then taken up indiethyl ether. The ether solution was washed with sodium bicarbonate,then with water to neutrality. The ether solution was dried over sodiumsulfate, filtered and concentrated on a rotary evaporator. The reducedesters (1 13 g. were distilled under vacuum to give 40.9 g (22 percentyield from diethyl vinyl phosphonate (DEVP) of 11a, n D 1.3538; 9.3 g ofintermediate fraction, n D 1.3694; 42.3 g (35 percent yield from DEVP)of 11b, n D 1.3857; and 14.2 g of residue. The residue was stirred withabsolute ethanol and filtered to give a fine brown solid (unidentified).The filtrate was concentrated to give a dark brown liquid believed to beanother telomer, n 3.

Redistillation of a portion of Ila gave bp 82-84C (0.05 mm).

Anal. Calcd. for C, H F O P: C, 29.23; H, 2.64: F, 53.35; P, 5.80.Found: C,-29.34; H, 2.84; F, 53.18; P, 5.59.

llb had bp 138140C (0.05 mm).

Anal. Calcd for C H F O P C, 32.68; H, 3.90; F, 40.81; P, 8.87; mol.wt., 698. Found: C, 32.73; H, 4.00; F, 40.88; P, 8.69; mol. wt.(chloroform), 702.

Anal. Solid residue; C, 28.79; H, 3.36; F, 29.35; P,

Anal. Liquid residue: Calcd. for C H F O P C, 34.82; H, 4.67; F, 33.04;P, 10.77. Found: C, 33.37; H, 4.33; F, 31.34; P, 9.79.

EXAMPLE 3 1H, 1H, 2H,2H-perfluorononylphosphonic dichloride (llla) 11a(40 g, 0.075 mole) was heated with 100 ml of conc. hydro-chloric acid atgentle reflux for 3 hours. The mixture was concentrated under vacuum toa gelatinous mass. Conc. hydrochloric acid (75 ml) was added to themixture and refluxed overnight. The mixture was again concentrated undervacuum. Benzene was added and the remaining water removed by azeotropicdistillation into a Dean-Stark trap. After removal of benzene, the solidresidue was dried under vacuum at 105C to a constant weight to give thecrude acid-adduct. This crude acid was dispersed in carbon tetrachlorideand added to a rb flask equipped with a magnetic stirrer, condenser anddrying tube. The mixture was heated to gentle reflux then phosphoruspentachloride (36.6 g, 0.176 mole) was added cautiously in smallportions through the condenser. The addition was completed in 30minutes, and the solution refluxed overnight. Sulfur dioxide was bubbledthrough the warm solution to remove excess phosphorus pentachloride. Thesolution was concentrated under water aspirator vacuum, and the residuedistilled at 69-72C (0.04 mm) to give an 83 percent yield (32.2 g, 0.062mole) of Illa, a white solid.

Anal. Calcd. for C H Cl F OP: C, 20.99; H, 0.78; C], 13.77; F, 55.34; P,6.01. Found: C, 20.79; H, 0.89; Cl, 13.76; F, 55.13; P, 5.99.

EXAMPLE 4,

1-( 1H, lH-perfluorooctyl)-l ,3- trimethylenediphosphonic tetrachloride(Illb) llb (57.8 g. 0.083 mole) was heated at gentle reflux for 6 hourswith conc. hydrochloric acid (300 ml) in a one liter rb flask equippedwith a 500 ml defoamer-bulb and a condenser. The mixture was cooled inthe refrigerator and the liquid decanted from the solid. Morehydrochloric acid was added and the procedure repeated. The gel-likematerial was concentrated in a large evaporating dish on the steam coneusing benzene to remove residual water. The solid residue was driedunder vacuum at 105C. to a constant weight to give the crudeacid-telomer, which was then reacted with phosphorus pentachloride asdescribed for the crude acid-adduct above. lIIb was distilled at 125-126(0.01 mm) to give a 40 percent yield (21.7 g, 0.033 mole) of a slightlyyellow solid.

Anal. Calcd for C H Cl F O P z C 20.02; H, 1.07; Cl, 21.49; F, 43.18; P,9.39; mol. wt., 660. Found: C,

20.16; H, 1.14; Cl, 21.54; 43.29; P, 9.21; mol. wt.

(chloroform), 673

EXAMPLE 5 1 H, l H,2H,2H-perfluorononylphosphonic acid (lVa) lIla (2 g,0.004 mole) was dissolved in chloroform,

trimethylenediphosphonic acid (lVb) lVb was prepared from 11112 asdescribed for IVa except it was dried to constant weight in a vacuumdesiccator at room temperature.

Anal. Calcd for C H F O P z C, 22.54,'H, 1.89; F, 48.62; P, 10.57.Found: C, 22.75; H, 1.95; F, 48.68; P, 10.77.

EXAMPLE 7 1 H, lH,2H,2l-l perfluorononylbis( 1-aziridinyl)phosphineoxide (Va) Redistilled triethylamine (12.6 g,

.0.l24 mole) and redistilled aziridine (5.4 g. 0.124

mole) in carbon tetrachloride (100 ml) was added to a 4-neck rib flaskequipped with a mechanical stirrer, thermometer, dropping funnel andcondenser with drying tube. The flask was cooled to 5 in an ice bath.Illa (29 g, 0.056 mole) in ml of carbon tetrachloride was added from thedropping funnel at such a rate as to keep the reaction temperature below10. After the addition, the reaction temperature wasallowed to rise toroom temperature. The reaction mixture was heated at 35-40C withstirring for 1 hour. The copious white precipitate was removed by vacuumfiltration, rinsed thoroughly with carbon tetrachloride and dried togive 14.7 g percent yield) of triethylamine hydrochloride. The filtratewas cooled at 0 overnight then filtered by gravity through sodiumsulfate. The

clear filtrate was concentrated to approximately 125 ml on a rotaryevaporator below 40C. The solution was treated with decolorizing carbonand sodium sulfate then filtered by vacuum through diatomaceous earth.The filtrate was again concentrated to approximately 75 ml then 150 mlof petroleum ether (3060C) was added. The solution was stored at 20 for1 hour. The liquid was decanted through filter paper (filtrate No. l).The slurry of white precipitate was redissolved in 100 ml of petroleumether and stored at 20C overnight. The white waxy precipitate wasfiltered by vacuum, washed thoroughly with cold petroleum ether anddried in a desiccator to give 8.9 g of Va, mp 4950 average aziridinylassay of duplicate samples, 99.7%. The concentrated filtrate was dilutedwith petroleum ether and a second crop. of crystals (10.1 g) wasobtained; mp 4244C, average aziridinyl assay of duplicate samples, 97.7percent. The filtrate was combined with filtrate No. 1 and concentratedto a yellow solid residue (7.1 g). The first and second crop of crystalsgave a 64 percent yield of Va.

Anal. Calcd for C H F N OP: C, 29.59; H, 2.29; F, 53.95; N, 5.30; P,5.86; mol. wt., 528. Found: C, 29.50; H, 2.41; F, 54.00; N, 5.33; P,5.78; mol. wt. (methanol), 530.

EXAMPLE 8 1-(1H,lH-perfluorooctyl)-l,3-trimethylenebis[di(laziridinyl)phosphine oxide] (Vb) Vb was prepared from lVb as described for Va togive a 64 percent yield; mp 103-l07C; aziridinyl assay 97.3 percent. (Vbwas obtained as a slightly purer product when dissolved in carbontetrachloride and a polymeric material removed by filtration; aziridinylassay, 100.2 percent).

Anal. Calcd for C 1-1 F N O P C, 33.25; H, 3.38; F, 41.52; N, 8.16; P,9.03; mol. wt., 686. Found: C, 33.07; H, 3.14; F, 41.42; N, 8.08; P,9.15; mol. wt. (chloroform), 691.

APPLICATION TO COTTON FABRIC In all of the following examples cottonprintcloth was used. In some cases the cloth contained the wash-wearfinish, dimethylol ethylene urea. The printcloth was immersed in thesolution and the excess squeezed out by passing through squeeze rolls toa wet pickup of 80-85 percent. The fabric was then dried and cured in aforced draft oven, and finally rinsed and dried.

The two compounds used in the following examples are 1 H,1H,2H,2H-perfluoronony1bis( l-aziridinyl)phosphine oxide and l-( l H, 1H-perfluoroooctyl)- l,3-trimethylene-bis[di(1-aziridiny1)] phosphineoxide. For brevity the two compounds will be designated F- NAPO andtelomer, respectively. The term oil rating will be abbreviated OR.

EXAMPLE 9 A solution was prepared by dissolving FNAPO (0.5 grams) in acombination of water (4.5 grams) and ethanol (5.0 grams). The solutioncontained 5 percent FNAPO by weight. A sample of print-cloth wasimmersed in l percent aqueous zinc fluoborate, the excess squeezed out,and the fabric dried. The thus impregnated fabric was then impregnatedwith the FNAPO solution, dried for 30 minutes at room temperature andcured for 20 minutes at 120C. The fabric had an oil rating (OR) of 5.The fabric had an OR of 2 after five laundering cycles and an OR of 5after 3 hours extraction with tetrachloroethylene in a Soxhletextractor.

EXAMPLE 10 Printcloth was treated as in Example 9 except that thesolvent was ethanol instead of water-ethanol and the fabric was curedfor 5 minutes at 150C. The OR of the fabric was 6. After 5 launderingsthe OR was 2.

EXAMPLE 1 l Printcloth was treated as in Example 9 except that thesolvent was ethylene glycol monoethyl ether, and 2% zinc fluoborate wasused, and the fabric was dried for 3 minutes at C. The OR of the fabricwas 6. After 5 launderings the OR was 3.

EXAMPLE 12 that a 3% aqueous solution of FNAPO containing 0.6%

zinc fluoborate was used. Similar results on oil and water repellencyand strength retention were obtained.

EXAMPLE 13 The two treatments in Example 12 were repeated except thatthe fabric used was treated with dimethylol ethyleneurea to impartwash-wear properties prior to treatment with FNAPO. Similar results onoil and water repellency were obtained. Fabric strength was lower due tothe wash-wear finish.

EXAMPLE 14 Cotton printcloth was impregnated with an aqueous solutioncontaining 5% FNAPO and 0.5% zinc fluoborate. The fabric was dried for 5minutes at C and cured for 5 minutes at C. The OR was 6. After 5launderings in a Tergitometer the OR was 2, and after a 3 hourextraction in a Soxhlet extractor the OR was 5.

EXAMPLE 15 Two printcloth samples were treated as in Example 14 except1% zinc fluoborate was used and one sample was cured for 3 minutes at C,and the other cured for 10 minutes at 160C. The first sample had an ORof 5. After 5 launderings in a Tergitometer the OR was 3. The secondsample had an original OR of 6, and an OR of 3 after 5 launderings in aTergitometer. The OR of the samples was unaffected by extraction withtetrachloroethylene.

EXAMPLE 16 Cotton printcloth was impregnated with an aqueous solutioncontaining 10% FNAPO and 1% zinc fluoborate. The fabric was dried forminutes at 85C and cured for 5 minutes at 160C. The OR was 6 before andafter extraction with tetrachloroethylene and 4 after five Tergitometerlaunderings.

EXAMPLE l7 Printcloth was treated as in Example 16 except a 5 percentsolution of FNAPO was used and the fabric was cured for 30 minutes at120 without predrying. The OR was 6 before and after tetrachloroethyleneextraction.

EXAMPLE 18 We claim:

1. A single bath process for imparting to cotton textiles oil and waterrepellency comprising:

a. impregnating the cotton textile with a water solution containing acompound selected from the group consisting of1H,ll-l,2l-l,2H-perfluorononylbis (l-aziridinyl)phosphine oxide andl-(1I-l,1l-lperfluorooctyl)- l ,3-trimethylenebis[di(l-aziridinyl)phosphine oxide], and about from 0.5 to 2 percent of alatent acid catalyst, and

. drying and curing the wet impregnated textile at temperatures aboutfrom to C, 'for periods of time about from 3 minutes to 30 minutes,using the longer times with the lower temperatures.

2. The cotton textiles prepared by the process of claim 1 where thecompound employed is 1H,1H,2 H,2H-perfluoro-nonylbis(l-aziridinyl)phosphine oxide.

3. The cotton textiles prepared by the process of claim 1 where thecompound is 1-( l H,lH-perfluorooctyl)-1,3-trimethylenebis[di(l-aziridinyl)phosphine oxide].

1. A single bath process for imparting to cotton textiles oil and waterrepellency comprising: a. impregnating the cotton textile with a watersolution containing a compound selected from the group consisting of 1H,1H,2H,2H-perfluorononylbis (1-aziridinyl)phosphine oxide and1-(1H,1H-perfluorooctyl)-1,3-trimethylenebis(di(1-aziridinyl)phosphineoxide), and about from 0.5 to 2 percent of a latent acid catalyst, andb. drying and curing the wet impregnated textile at temperatures aboutfrom 120* to 160*C, for periods of time about from 3 minutes to 30minutes, using the longer times with the lower temperatures.
 2. Thecotton textiles prepared by the process of claim 1 where the compoundemployed is 1H,1H,2H,2H-perfluoro-nonylbis(1-aziridinyl)phosphine oxide.